Every year about 5% of iron products worldwide are being replaced due to corrosion. Various coating methods are used to reduce the corrosion damage, most of which methods are based on applying paints. The corrosion protective element in paints is generally a corrosion inhibitor based on chromates. These corrosion inhibitors usually include heavy metals salts, which hinder the corrosion of the metal surface. Zinc compounds such as zinc phosphate and zinc chromate are currently widely used as corrosion inhibitors. Zinc is a heavy metal element and is considered to be toxic at certain concentrations.
Furthermore, the damaging effects of corrosion on cooling systems cause an equipment failure and loss of system efficiency, which can be even more costly over time. Conventional cooling water corrosion inhibitors such as zinc, chromate, molybdate and nitrites are all toxic to the environment and in most cases damaging to human health. Due to the growing awareness of the environmental damage associated with heavy metal products, there is an industrial need for effective corrosion inhibitor coating methods based on non heavy metals, non-toxic agents.
Steel corrosion in reinforced concrete structures has been a major problem across the U.S. Steel-reinforced concrete structures are continually subject to attack by corrosion brought on by naturally occurring environmental conditions such as carbonation and the introduction of chlorides from sources such as salt water, deicing salts, and accelerating admixtures.